Non-halogenated metal conditioner and extreme pressure lubricant

ABSTRACT

There are disclosed compositions for use as extreme pressure lubricants for use in general machinery as well as in the refrigerant of air conditioners, refrigerators and heat pumps. The compositions are designed to lubricate moving parts of machinery. In its broadest aspect the invention comprises a metal conditioner containing a lubricating oil and a bismuth compound. A further embodiment involves a lubricating oil, a bismuth compound and a molybdenum compound. The lubricating compounds can be added to a refrigerant gas.

FIELD OF THE INVENTION

[0001] The herein disclosed invention finds applicability in the fieldof extreme pressure lubrication. Examples of areas needing this type oflubrication are machinery in general and particularly refrigeration andair-conditioning systems, heat pumps and compressors wherein thelubricant is added to circulate in the compressor system reservoir andbearing surfaces, etc.

BACKGROUND OF THE INVENTION

[0002] There is a need in industry for a lubricating and/or conditioningsystem for lubricating metal surfaces, especially in refrigeration andair conditioning systems. It is desirable that the lubricating system befree of chlorine, sulfur, and fluorine which have the potential ofcombining with hydrogen to produce hydrochloric, sulfuric, andhydrofluoric acid, respectively.

[0003] In the field of specialty lubrication, active elements such assulfur, chlorine, fluorine, lead, etc. have been used to provide extremepressure (EP), anti-wear, anti-friction properties. In this era ofincreased environmental concerns, the use of these types of elements,regardless of their ability to improve lubrication performance, adds tothe hazardous waste stream and increases the cost of production if usedin industry.

[0004] In some cases, chemical compound break-down can release theelement to form other compounds which are corrosive, such as sulfuricacid, hydrochloric acid, etc.

[0005] Prior Art U.S. Patents

[0006] Wilkins, et al (U.S. Pat. No. 4,963,280) teaches compositions forimproving the efficiency of heat pumps, refrigeration units, aircondition and heating units. The patentees do this by employing a polarorganic compound which is defined as being an organic compoundcontaining sufficient polar groups to provide regions on the moleculewhich have regions of high electron densities and other regions whichhave low electron densities. The preferred polar compounds are liquidhalogenated α-olefins and liquid halogenated paraffins.

[0007] Karol, et al (U.S. Pat. No. 5,576,273) teaches a synergisticmixture of a dithiocarbamate and organic bismuth compounds to have goodextreme pressure properties and to be useful in lubricatingcompositions.

[0008] Karol et al (U.S. Pat. No. 5,631,214) teaches the preparation ofbismuth dithiocarbamates for use as extreme pressure additives.

[0009] Sgarbi, et al (U.S. Pat. No. 6,276,147) teaches a polar solutionfor air conditioning and refrigeration containing a dithiocarbarnate anda calcium salt.

[0010] Sgarbi, et al (U.S. Pat. No. 6,286,323) teaches compositions forimproving air conditioning and refrigeration systems containing a polarcompound, dithiocarbamates, β-olefin (see claim 1) and other ancillarycomponents are set forth.

[0011] Roberts (U.S. Pat. No. 6,110,877) teaches an extreme pressurelubricant composition containing amongst other ingredients bismuthcompounds and a polyalphaolefin (e.g., 1-decene homopolymer).

[0012] Rowan et al (U.S. Pat. No. 4,889,647) sets forth molybdenumcompounds useful in lubricants.

OBJECTS OF THE INVENTION

[0013] A principal object of this invention is to produce an active,polarized refrigerant oil additive and extreme pressure lubricant whichwill significantly improve heat transfer in the condenser and evaporatorcoils of a refrigeration system.

[0014] A further object of this invention is to produce a lubricantwhich efficiently functions as an extreme pressure lubricant in thecompressor unit of refrigerators, chillers, freezers, heat pumps and airconditioners.

[0015] An important object of the invention is to provide an active,polarized refrigerant oil additive and extreme pressure lubricant thatdoes not contain halogen or sulfur as the polarizing agent.

[0016] An additional object is to produce an extreme pressure lubricantwhich is environmentally friendly.

[0017] A main object of this invention is to produce an extreme pressurelubricant which will efficiently lubricate the metal surfaces of acompressor system.

[0018] An important object of the invention is to provide an extremepressure lubricant for refrigerants that does not contain halogen orsulfur as the polarizing agent.

[0019] A significant object of this invention is to produce acomposition when properly used will decrease energy use, boost lubricitybetween metal to metal contact and increase efficiency.

[0020] These and other objects of the present invention will becomeapparent from a reading of the following specification.

[0021] Identification and/or Source of Components of the InventivePolarized Additive, Metal Conditioner and Extreme Pressure Lubricantare: Component Identification Polyalphaolefin Base Oil CAS: 88037-01-4Methyl Ester Base oil CAS: 68082-78-0 Fatty Acid Ester Base Oil CAS:68424-31-7 Bismuth Carboxylate CAS: 34364-26-6 26896-20-8 ViscosityImprover Copolymer of Ethylene & (Paratone ™ 8232) Propylene (Olefins)Antimony Dialkyldithiocarbamate VANLUBE ™ 73 (mixture) ZincAlkyldithiophosphate LUBRIZOL ™ 5178-F (mixture) Organomolybdenumcomplex of MOLYVAN 855 (mixture) Organic Amide DialkyldithiocarbamateEster with OD-9413 (mixture) Bismuth Carboxylate Epoxidized TriglyceridePlas-Check 775 ™ Acid Scavenger/Stabilizer

[0022] Olefin blend can be obtained as polyalphaolefin under the tradenames Ethyl Flo 166, Durasyn 166 or Synfluid PAO6 (Chevron-PhillipsCo.).

[0023] Examples of operative bismuth carboxylates are bismuthneo-decanoate (CAS: 34364-26-75), bismuth 2-ethylhexanoate and bismuthnaphthenate or mixtures of these bismuth compounds and are availablefrom OMG™ Cleveland, Ohio or R. T. Vanderbilt™ of Norwalk, Conn.

[0024] Polyalphaolefin is a hydrogenated synthetic hydrocarbon basefluid supplied by the Ethyl™ Corporation and has a CAS registry numberof CAS: 68037-014.

[0025] Amoco™ supplies 1-decene, Homopolymer Hydrogenated and has a CASNo. 88037-01-4.

[0026] Examples of fatty acid base oils CAS: 68082-78-0, synonsym:methyl lardate, available from Ferro Corporation, Hammond, Ind.

[0027] Example of penteryiitol esters of C₅-C₁₀ fatty acid are CAS:68424-31-7.

[0028] Molybdenum compound can be obtained from R T. Vanderbilt™ underthe designation Molyvan 855.

[0029] Dialkyldithiocarbamate Ester with Bismuth Carboxylate can beobtained from R. T. Vanderbilt™ under the designation OD-9413.

[0030] Epoxidized triglyceride can be obtained from Ferro™ as Plas-Check755™.

[0031] Further examples of the active components used in the lubricantand metal conditioner of this invention are to be found in U.S. Pat. No.6,110,877 and bismuth carboxylates are to be found in U.S. Pat. No.5,576,273.

[0032] Exemplary of the refrigerant gas to which the lubricant metalconditioner is to be added are CFC, HCFC and HFC:C=carbon, F=fluorine,H=hydrogen). The refrigerant gases are conventional in the art, andspecific examples are fluoropropane and fluorobutane. Additionally, thisinvention is compatible with refrigerants from the Freon series andtheir updated replacements, as well as the Methane series, the Ethaneseries, and the Propane series, Ammonia, Sulfur Dioxide and CarbonDioxide gasses.

BRIEF SUMMARY OF THE INVENTION

[0033] In its broadest aspect the herein disclosed invention is directedto the incorporation of effective amounts of a bismuth compound into therefrigerant oil reservoir or the refrigerant gas of a cooling systemsuch as chillers, coolers, refrigeration plants, air conditioners,refrigerators and heat pumps. Generally speaking, the bismuth compoundwould be added along with a lubricant to the refrigerant gas or oil. Inpreferred embodiments, the bismuth compound will be present at about 5to 10 percent of the lubricating or refrigerant oil, however, theoptimum effective amounts could be determined by those skilled in theart. It is expected that the addition of a polarized lubricating oil andbismuth compound to refrigerant gas will boost metal-to-metal lubricityproducing a decrease in energy consumption and an increase of over-allefficiency of the cooling equipment in which the polarized bismuthcompound which is non-toxic is employed. The bismuth containinglubricating composition is intended to prolong the life of compressorsused in cooling equipment.

[0034] It is anticipated that dye tracers and/or bactericides may beadded to the bismuth containing lubricant composition.

[0035] Broadly considered the herein disclosed non-halogenated metalconditioner and extreme pressure lubricant additive useful inrefrigerant gas comprises effective amounts of:

[0036] a lubricant

[0037] bismuth carboxylate polarized extreme pressure additive,

[0038] an antimony dialkyldithiocarbarnate anti-wear additive,

[0039] a viscosity improver,

[0040] and a molybdenum compound anti-friction additive,

[0041] optionally, a dialkyldithiocarbamate ester with bismuthcarboxylate,

[0042] and/or an acid scavenger/stabilizer together in the compressorgas of a cooling unit.

[0043] The lubricant may comprise:

[0044] a polyalphaolefin base oil,

[0045] a methyl ester base oil,

[0046] a fatty acid ester base oil.

[0047] The herein disclosed lubricant composition is directed to anon-halogenated (no chlorine, fluorine, bromine, iodine, or astatine)metal conditioner/extreme pressure lubricant additive system, for use inthe conditioning or lubricating of metal surfaces. This formulation isunique in that it is free from chemical elements of the Halogen Group,particularly chlorine and fluorine, which are known to combine withhydrogen and form highly undesired (corrosive) hydrochloric acid andhydrofluoric acid respectively. Applications of the invention includebut are not limited to use as a Polarized Refrigerant Additive Oil(PROA) in consumer, industrial, commercial, military, and federal sectorrefrigeration and air conditioning systems, chillers and heat pumps andcompressors. Use of this additive system as a PROA provides (1)significantly improved heat transfer in the evaporator and condensingcoils, and (2) increased lubricity of refrigerant oils, significantlyenhancing compressor operation and efficiency. The additive system isblended into the refrigerant oil reservoir or refrigerant flow asappropriate to the equipment design. When used as a polarizedrefrigerant oil and lubricant additive, the composition of thisinvention is carried with the primary lubricant and moves throughout thesystem. The polar nature of the formula refers to the covalent molecularbonding which takes place between the negatively charged additivemolecules and the positive charge of the metal surfaces. As eachmolecule attaches itself to metal surfaces within the system, itconditions these surfaces, displacing dirt, carbon deposits (coking),and lubricating oil build-up, eventually forming a thin, one moleculethick layer of the additive system. This provides the optimal conditionsfor efficient thermal conductivity within the heat exchanger systems ofrefrigeration/air conditioning equipment. Additionally, as a polar(molecular bonding) extreme pressure lubricant, it provides greatlyenhanced lubrication to moving parts of refrigeration equipment.

[0048] The lubrication system may include in combination, apolyalphaolefin base oil, a methyl ester base oil, a fatty acid esterbase oil (individually or as a mixture), a bismuth carboxylate polarizedextreme pressure additive, a viscosity improver, a molybdenumanti-friction additive, and optionally, an additional bismuth compoundadditive, and/or an acid scavenger/stabilizer. In an embodiment when inoperation, the lubricant additive system is present in a minor quantityand the primary lubricating oil or refrigerant is present in a majorquantity, based on weight. In a preferred embodiment, the bismuthcarboxylate is selected from the group of bismuth neodecanoate, bismuth2-ethylhexanoate, bismuth naphthenate and mixtures thereof. Thepolyalphaolefin base oil is from about 20 to 40 percent of said additivesystem and preferably from about 28 to 38 percent of the additivesystem. The methylester base oil is from about 15 to 35 percent of theadditive system and preferably from about 24 to 33 percent of saidsystem. The fatty acid ester base oil is from about 1 to 10 percent ofsaid additive system and preferably from about 2 to 5 percent of theadditive system. The bismuth carboxylate is present in the range fromabout 20 to 40 percent, and preferably from about 23 to 32 percent.About 1 to 8 percent of an olefin blend is employed in the system as aviscosity improver, preferably in the amount from about 3 to 5 percentof the additive system as a copolymer of ethylene and propylene. Amolybdenum compound may be introduced from about 0.1 to 8 percent of thesystem. Optionally, an additional bismuth compound may be introducedfrom about 0.1 to 8 percent of the system. Optionally, about 1 to 3percent of an epoxidized triglyceride may be employed in the system asan acid scavenger and/or stabilizer.

[0049] Note particularly that the lubricant composition does not containchlorine or sulfur compounds which would adversely affect the componentsof the air conditioner, refrigerator or heat pump.

[0050] In a preferred embodiment of this invention, there is envisionedthe following composition for addition to the refrigerant of thecompressor of, for example, air conditioners, refrigerators and heatpumps in approximately the following proportions: Component PercentPolyalphaolefin Base Oil 32.58 Methyl Ester Base oil 28.00 Fatty AcidEster Base Oil 3.06 Bismuth Carboxylate 27.00 Viscosity Improver 4.00(Paratone ™ 8232).

[0051] To this preferred embodiment, optional alternative ingredientscan be added to tailor the product to a particular industry, applicationor customer. For example, epoxidized triglycerides 1-2 percent can beadded. Another component contemplated for use is an anti-microbialbiocide as, for example, ionic silver.

[0052] A special embodiment of this invention includes the addition of atracer dye, e.g., fluorescent tracer dye, to the lubricant which is tobe supplied to the refrigerant of the cooling unit.

[0053] While the invention has been defined in terms of airconditioners, refrigerators or heat pumps, the invention is intended tocover like devices which involve refrigerant gases.

[0054] An elegant embodiment of this invention involves a lubricatingcomposition for lubricating gear boxes as well as a lubricatingcomposition for compressors. Broadly considered this elegant compositioncomprises effective amounts of bismuth compound, molybdenum compound andlubricating oil as for example: Component Percent Lubricating oil 40-70Bismuth compound 20-40 Molybdenum compound  1-20

[0055] In addition, a zinc compound can be added to this composition inthe range of 0.1-2%. An antimony compound may be added in the range of1-10%. The composition may also be added to a refrigerant gas and canalso be accompanied by a tracer to detect leaks. Antimicrobial agentsmay be added as a preservative. In this latter respect, silvercontaining antimicrobial agents are preferred. A viscosity improver withan SAE iso-number of 32-68 would be an operative additive for thecomposition.

[0056] A specific preferred embodiment of the conditioner-lubricatingcomposition involves: Component Percent Bismuth compound 30 Molybdenumcompound 6 Lubricating oil 64

[0057] Rowan et al (U.S. Pat. No. 4,889,647) is exemplary of molybdenumcompounds useful in the herein disclosed invention and is incorporatedby reference to show the same.

[0058] The amounts of the ingredients set forth herein are exemplary andcould be varied somewhat as readily understood by those skilled in theart. Effective amounts of the ingredients could also be determined bythose skilled in the art.

[0059] In general, any type of lubricant or lubricating oil would beappropriate. The terms lubricant and lubricating oil may be usedinterchangeably.

[0060] Obviously, many modifications may be made without departing fromthe basic spirit of the present invention. Accordingly, it will beappreciated by those skilled in the art that within the scope of theappended claims, the invention may be practiced other than has beenspecifically described herein.

What is claimed is:
 1. A non-halogenated metal conditioner and extremepressure lubricant additive useful in the refrigerant gas of an airconditioner, refrigerator or heat pump comprising in combination arefrigeration gas, effective amounts of a lubricant and a bismuthcompound.
 2. The non-halogenated metal conditioner and extreme pressurelubricant additive of claim 1 wherein the lubricant comprises apolyalphaolefin base oil.
 3. The non-halogenated metal conditioner andextreme pressure lubricant additive of claim 1 wherein the lubricant amixture polyalphaolefin base oil, methyl ester base oil and fatty acidester base oil.
 4. The non-halogenated metal conditioner and extremepressure lubricant additive of claim 1 wherein the bismuth compound is abismuth carboxylate.
 5. The non-halogenated metal conditioner andextreme pressure lubricant additive of claim 4 wherein the bismuthcarboxylate is selected from the group of bismuth neodecanoate, bismuth2-ethylhexanoate, bismuth naphthenate and mixtures thereof.
 6. Thenon-halogenated metal conditioner and extreme pressure lubricantadditive of claim 1 wherein there is added a composition of (a) abisdithiocarbamate and (b) a bismuth compound of carboxylates,dithiocarbamates, and phosphorodithioates.
 7. The non-halogenated metalconditioner and extreme pressure lubricant additive of claim 1 whereinthere is added a molybdenum compound as an anti-friction additive. 8.The non-halogenated metal conditioner and extreme pressure lubricantadditive of claim 1 wherein there is added a tracer dye to aid in leakdetection.
 9. A method for enhancing lubricity of a refrigeration unitcomprising adding the composition of claim 1 to said refrigeration unit.10. A non-halogenated metal conditioner and extreme pressure lubricantadditive useful in refrigerant gas comprising effective amounts of: alubricating oil, a bismuth carboxylate polarized extreme pressureadditive, a viscosity improver, a molybdenum compound anti-frictionadditive, and/or an acid scavenger/stabilizer together in the compressorgas of a cooling unit.
 11. A non-halogenated metal conditioner andextreme pressure lubricant additive useful in the refrigerant gascomprising the following: Component Percent Lubricating oil 64.00Bismuth Carboxylate 27.00 Viscosity Improver 4.00 Molybdenum compound5.00

12 The non-halogenated metal conditioner and extreme pressure lubricantadditive useful in compressor refrigerant gas of claim 1 wherein thefollowing ingredients are present on a weight basis: lubricating oil 40to 70 percent bismuth carboxylate is present in the range from about 20to 40 percent, about 1 to 8 percent of an olefin blend is employed inthe system as a viscosity improver, as a copolymer of ethylene andpropylene, a molybdenum compound may be introduced from about 0.1 to 8percent, optionally, about 1 to 3 percent of an epoxidized triglyceridemay be employed in the system as an acid scavenger and/or stabilizer,optionally, an additional bismuth compound may be introduced from about0.1 to 8 percent.
 13. The non-halogenated metal conditioner and extremepressure lubricant additive useful in compressor gas of claim 1 whereinthe following ingredients are present on a weight basis: polyalphaolefinbase oil is from about 28 to 38 percent, methyl ester base oil is fromabout 24 to 33 percent, fatty acid ester base oil is from about 2 to 5percent, bismuth carboxylate is present in the range from about 23 to 32percent, about 3 to 5 percent of an olefin blend is employed in thesystem as a viscosity improver, as a copolymer of ethylene andpropylene, a molybdenum compound may be introduced from about 0.1 to 8percent, optionally, about 1 to 3 percent of an epoxidized triglyceridemay be employed in the system as an acid scavenger and/or stabilizer.14. A non-halogenated metal conditioner and extreme pressure lubricantcomprising effective amounts of: Bismuth compound. Molybdenum compound,and Lubricating oil.
 15. The non-halogenated metal conditioner andextreme pressure lubricant of claim 14, comprising: Component PercentBismuth compound 20-40 Molybdenum compound  1-20 Lubricating oil  40-70.


16. The non-halogenated metal conditioner and extreme pressure lubricantof claim 15 comprising: Component Percent Bismuth compound 30 Molybdenumcompound  6 Lubricating oil 
 64.


17. The non-halogenated metal conditioner and extreme pressure lubricantof claim 14 further comprising a refrigerant gas.
 18. In the method ofoperating an apparatus having a refrigerant gas circulating therein,wherein a lubricant is added to the refrigerant gas to provide extremepressure, anti-wear and anti-friction properties, the improvementcomprising the step of adding effective amounts of bismuth compound tothe lubricant in lieu of halogens or sulfur compounds as the polarizingagent, thereby substantially reducing corrosion and environmentalproblems while concurrently improving the efficiency, life andreliability of the apparatus.
 19. In the method of claim 18 wherein theimprovement further comprises the step of adding effective amounts of amolybdenum compound to the lubricant.